phe·​nan·​thro·​line | \ fə̇ˈnan(t)thrəˌlēn, -lə̇n\
plural -s

Definition of phenanthroline

: any of three crystalline nitrogen bases C12H8N2 related to phenanthrene and derivable from ortho-, meta-, and para-phenylenediamine; di-aza-phenanthrene especially : the ortho or 1,10-isomer that forms a red coordination complex with ferrous ions useful as an oxidation-reduction indicator (as with potassium permanganate as oxidizing agent) because it becomes faint blue in the oxidized form

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History and Etymology for phenanthroline

International Scientific Vocabulary phenanthr- + quinoline

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